The Chester class of light cruisers were the first United States Navy vessels to be designed and designated as fast Scout cruisers for fleet reconnaissance. In 1920 the Scout Cruisers were redesignated Light Cruisers. The three ships were built to slightly different designs for the sake of comparison: Chester was the first major combatant in the USN to have steam-turbine propulsion, of the Parsons type; Salem received Curtis turbines and Birmingham traditional reciprocating steam engines. Birmingham was the first ship in the world to launch an airplane, in 1910.